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所在平台: Udemy |
课程主页: https://www.udemy.com/course/atomic-structure/
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**课程名称：原子结构 (Atomic Structure)** **课程概述：** 本课程深入探讨了原子的基本构成和历史发现过程。课程指出，原子在整体上是电中性的，这意味着它必然包含带负电的电子以及带等量正电的粒子。亚原子粒子的存在，特别是质子的概念，源于卢瑟福通过α射线轰击元素进行的著名实验。 课程还将介绍卢瑟福实验的背景，包括放射性元素释放α射线的现象。此外，课程将追溯中子的发现历程，强调1932年詹姆斯·查德威克通过α射线轰击铍元素成功发现了中子。 在电荷方面，课程明确指出电子带有负电荷，而质子带有等量的正电荷，两者电荷量大小相等但符号相反。中子则不带电荷。 课程将追溯电子存在的早期推测，重点介绍J.J. Thomson在低压气体导电性实验中对阴极射线的研究，以及Becquerel、Curies夫妇和Rutherford在放射性研究中的贡献。 课程还将详细介绍J.J. Thomson等人对阴极射线的重要性质的探索，包括： * 阴极射线垂直于阴极表面发射，并沿直线传播。 * 其传播路径不受阳极位置的影响。 * 它们能在某些盐类（如ZnS）上产生磷光，在玻璃上产生荧光。 * 阴极射线能够使感光板（照相底片）黑化。 * 它们可以穿透薄金属片，但如果金属片过厚，则会被阻挡并投下阴影。 * 当阴极射线撞击金属时，会产生X射线。 **教学大纲：** （无）
An atom is electrically neutral, and if it contains negatively charged electrons it must also contain some positively charged particles, and the supposition that they existed within atoms came aboutas a result of Rutherford's experiments in which he bombarded elements with the alpha - rays and alpha - rays were given off by radioactive elements. The neutron was discovered in 1932 by James Chadwick by bombarding beryllium with alpha rays.The electron and proton have equal, but opposite, electric charges; the neutron is not charged.The electron and proton have equal, but opposite, electric charges; the neutron is not charged.The existence of electrons in atoms was first suggested, by J.J. Thomson, as a result of experimental work on the conduction of electricity through gases at low pressures, which produces cathode rays and x-rays, and a study of radioactivity by Becquerel, the Curies and Rutherford.Some of the important properties of the cathode rays studied by Sir J.J. Thomson and others are:Cathode rays come out at right angles to the surface of the cathode and move in straight lines.Their path is independent on the position of the anode.They produce phosphorescence on certain salts like ZnS and fluorescence on glass.They blacken photographic plates.The rays pass through thin sheet of metals. If the metal sheet is too thick to be penetrated the rays cast a shadow.They produce X-ray when they strike a metal.
